Effect of powder characteristics and print processing parameters on printability, microstructure and mechanical properties of angular powders in powder bed additive manufacturing techniques

PI: Anthony D. Rollett
Co-PI(s): Amir Mostafaei
University: Carnegie Mellon University

In additive manufacturing based on powders, the feedstock is a substantial contributor to the final cost of the component. The current assumption is that near-spherical powders are required but success was obtained in the previous PITA project in demonstrating that low-cost but strongly non-spherical Hydride-Dehydride (HDH) Ti-6Al-4V powder can be used in an electron- beam Arcam printer. Ametek plans to work with CMU to build on this success and extend the use of HDH powder to both laser and binder jet powder bed technologies thereby bolstering an important component of the southwest PA economy. Powder characteristics such as morphology and size distribution are two main parameters affecting 3D printing processes in terms of powder bed density, printability and green part density. HDH and/or milled powders have angular particles that may decrease powder bed density especially during the spreading step; however, the production cost of these powders is ~25 % lower than atomization technique. Thus, the goal of the proposed project is to (1) develop a better understanding of powder characteristics of angular powder (e.g., morphology, size distribution, flowability) and (2) optimize processing parameters in powder bed techniques such that desired density and mechanical properties can be attained. This project utilizes effective collaboration between CMU and Ametek Powders to enable the use of angular powders in powder bed AM processes such as binder jet 3D printing (BJ3DP) and laser powder bed fusion (LPBF). Along with Ametek, other powder manufacturing companies in PA like ATI Powder Metals Research, General Carbide, Carpenter Powder Products, and Arconic will also benefit by the usage of non- spherical powders.